1. Field of the Invention
The present invention relates to an improvement in the production of serged trouser-fly pieces with slide fastener stringers attached thereto of the type wherein at least a corner of a leading end of the trouser-fly piece is trimmed along a substantially arcuate trimming line and, substantially at the same time, a serge stitching is formed on one longitudinal edge of the trouser-fly piece including the trimmed arcuate corner.
2. Description of the Related Art
A typical example of the serging process of the type concerned is described in U.S. Pat. No. 5,069,148 which has been assigned to the present assignee. According to the described serging process, an elongate rectangular trouser-fly piece attached to a slide fastener stringer chain of an individual fastener length is supplied to a serging machine having a trimming cutter. Subsequently, at least a corner of a leading end of the trouser-fly piece is trimmed by the trimming cutter along a substantially arcuate trimming line to form a curved longitudinal edge including the trimmed arcuate corner while the trouser-fly piece is being advanced by the serging machine. Substantially at the same time, the curved longitudinal edge of the trouser-fly piece including the trimmed arcuate corner is serged with a serge stitch to avoid raveling. The trouser-fly thus serged with the slide fastener stringer attached thereto can easily and neatly be attached to a trouser front with ornamental stitches, so called "J-stitches" because the curved longitudinal edge of the trouser-fly piece substantially conforms to a sewing line of the J-stitches. As against a conventional rectangular trouser-fly piece including a triangular flap portion extending outside the J-stitches, the trouser-fly piece having the arcuate corner neither makes the trouser front unsightly in appearance nor provides a sense of discomfort for the wearer of a pair of trousers.
However, due to the necessity of manually supplying the trouser-fly pieces of individual slide fastener lengths one by one to the serging machine, the foregoing serging process is relatively low in productivity and hence is not well suited for mass-production of trousers.